Obsessive Compulsive Disorder (OCD) is characterized by recurrent thoughts (obsessions) and/or repetitive rituals (compulsions) that are distressful and/or interfere in one's life (American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV), Washington, D.C.: American Psychiatric Association (1994)). The obsessive thoughts may include worries about the safety of oneself or family members, past actions, or fears of contamination. The rituals are often performed in response to an obsession and include repetitive washing, checking, counting, repeating, arranging, or hoarding. Childhood onset OCD has been reviewed by Swedo, et al., in Psychiatric Clinics of North America 15: 767 (1992). There is no known biologic marker or genetic marker, despite some evidence that childhood onset OCD may be biologically based. Lenane, et al., in J. of the American Academy of Child and Adolescent Psychiatry 29: 407 (1990), reported that parents of a patient group of children with OCD had an increased family rate of OCD, suggesting a genetic vulnerability for some.
Tourette's Syndrome (TS) or Tourette's Disorder is a childhood onset disorder characterized by involuntary motor and vocal tics of more than one year's duration which typically change anatomic location, number, frequency, complexity, and severity over time (DSM IV). Chronic motor tic, chronic vocal tic, and transient tic disorders are characterized by the same involuntary motor or vocal tics, but are not of sufficient duration to meet diagnostic criteria for TS (DSM-IV). Tic disorders and TS have been reviewed by Singer, et al., in Brain and Development 16: 353 (1994). There may be an association between OCD and tic disorders; as children with OCD have an increased rate of a comorbid (coexisting) tic disorder (Leonard, et al., Am. J. of Psychiatry 149: 1244 (1992)), and individuals with TS have an increased rate of obsessive compulsive symptoms (Pauls et al., Arch. Gen. Psychiatry 43: 1180 (1986)). Additionally, individuals with TS have an increased rate of familial OCD and tic disorders (Pauls et al., 1986).
Sydenham's Chorea (SC), first described in the late 1600s as "St. Vitus dance," is a type of rheumatic fever (RF) and is characterized by muscular weakness and chorea (reviewed by Swedo et al., in Pediatrics 91: 706 (1993)). The muscle weakness and adventitious movements may lead to a clumsy gait, slurred speech, and the inability to hold a grip. Historically, this neurological disorder has been described to have accompanying psychological symptoms in some patients, including emotional lability, irritability, and obsessive compulsive symptoms. Recently, some children with SC who had accompanying OCD, Attention Deficit Hyperactivity Disorder, emotional lability, and irritability have been described (Swedo et al., 1993).
Sydenham's chorea- is a variant of RF that is thought to result from an autoimmune process mediated by antineuronal antibodies. The self-reactive antibodies appear to arise in response to group A .beta.-hemolytic streptococci (GABHS) infections and then cross-react with antigens on neuronal cells within the basal ganglia and other brain regions (Husby et al., J. Exp. Med. 144: 1094 (1976)). The choreic symptoms could be caused either directly by antineuronal antibodies, or indirectly by altering immune responsivity or permeability of the blood brain barrier. Significantly, each of these mechanisms is reported to be under genetic control (Int. Rev. Cytol. 127: 57 (1991)).